1. Technical Field
The present invention relates to a thin film transistor for touch sensors, and more particularly, to a touch sensor including a nanowire array arranged perpendicular to an electrode.
2. Description of the Related Art
Touch sensors for sensing external force are broadly divided into a pressure sensitive type, a capacitive type, an infrared type, and an acoustic wave type depending upon implementation principles and operating methods thereof.
In recent years, technologies have been investigated to use a thin film transistor (TFT) as a touch sensor.
Particularly, there have been developed technologies for employing an insulation layer of a TFT with a vertical structure for a touch sensor. Such a touch sensor has a characteristic in that the insulation layer is partially changed in thickness under external force. This causes change in electrostatic capacity, thereby operating the touch sensor.
Although an insulation layer of a TFT is formed in a vertical structure in the related art, it is difficult to sense a fine substance such as a cell having a length of several micrometers or less, and fabrication processes are complicated.
In addition, touch sensors have been developed using a material exhibiting a piezoelectric effect, by which the material is compressed in response to applied force to induce electricity, and employed for electronic appliances such as keyboards. Touch sensors using such a material exhibiting the piezoelectric effect can be more simply and easily fabricated than existing touch sensors. However, touch sensors fabricated in film form still have difficulty in sensing fine substances.